Semiconductor device and a method for fabricating the same

ABSTRACT

A semiconductor device includes a first gate structure, a second gate structure, a first source/drain structure and a second source/drain structure. The first gate structure includes a first gate electrode and a first cap insulating layer disposed on the first gate electrode. The second gate structure includes a second gate electrode and a first conductive contact layer disposed on the first gate electrode. The first source/drain structure includes a first source/drain conductive layer and a second cap insulating layer disposed over the first source/drain conductive layer. The second source/drain structure includes a second source/drain conductive layer and a second conductive contact layer disposed over the second source/drain conductive layer.

RELATED APPLICATIONS

This application claims a priority of U.S. Provisional Application No.62/273,378 filed on Dec. 30, 2015, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The disclosure relates to a method for manufacturing a semiconductordevice, and more particularly to a structure and a manufacturing methodfor a self-align contact or a sacrificial layer structure oversource/drain regions.

BACKGROUND

With a decrease of dimensions of semiconductor devices, a sacrificiallayer structure (SAC) has been widely utilized for fabricating, e.g.,source/drain (S/D) contacts arranged closer to gate structures in afield effect transistor (FET). Typically, a SAC is fabricated bypatterning an interlayer dielectric (ILD) layer on the top of gatestructure and between sidewall spacers. The SAC layer is formed by adielectric filling and planarization after metal gate etches back. TheSAC layer on the top of gate, typically as nitride, creates a goodetching selectivity compared to the dielectric of ILD, which istypically oxide, on the top of S/D. This selective etching processimproves the S/D contact process window. As the device density increases(i.e., the dimensions of semiconductor device decreases), the thicknessof the sidewall spacer becomes thinner, which may cause a short circuitbetween the S/D contact and the gate electrodes. Accordingly, it hasbeen required to provide SAC structures to gain the process window ofthe formation electrical isolation between the S/D contacts and gateelectrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1A shows an exemplary plan view (viewed from the above)illustrating one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 1B shows an exemplary cross sectional view along lineX1-X1 of FIG. 1A. FIG. 1C is an enlarged view of the gate structureshown in FIG. 1B. FIG. 1D shows an exemplary perspective viewillustrating one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure.

FIGS. 2-13 show exemplary cross sectional views illustrating variousstages of the sequential fabrication process of a semiconductor deviceaccording to one embodiment of the present disclosure.

FIGS. 14-23 show exemplary cross sectional views illustrating variousstages of the sequential fabrication process of a semiconductor deviceaccording to another embodiment of the present disclosure.

FIG. 24 shows an exemplary cross sectional view illustrating one ofadvantages of the present embodiments.

FIG. 25 shows an exemplary layout structure according to one embodimentof the present disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the invention. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comp rising” or “consisting of.”

FIGS. 1A and 1B show one stage of a sequential fabrication process of asemiconductor device according to one embodiment of the presentdisclosure. FIG. 1A shows a plan (top) view and FIG. 1B shows a crosssectional view along line X1-X1 of FIG. 1A.

FIGS. 1A and 1B show a structure of a semiconductor device after metalgate structures are formed. In FIGS. 1A and 1B, metal gate structures 40are formed over a channel layer, for example, a part of a fin structure20 formed over a substrate 10. The metal gate structures 40 includes afirst to a fourth metal gate structures 40A, 40B, 40C and 40D, andextend in the Y direction and are arranged in the X direction. Thethickness of the metal gate structures 40 is in a range from about 20 nmto about 80 nm in some embodiments. Each of the gate structures 40includes a gate dielectric layer 42, a metal gate electrode 44 andsidewall spacers 46 provided on major sidewalls of metal gate electrode44. The sidewall spacers 46 are made of at least one of SiN, SiON, SiCN,or SiOCN. The film thickness of the sidewall spacers 46 at the bottom ofthe sidewall spacers is in a range from about 3 nm to about 15 nm insome embodiments, and is in a range from about 4 nm to about 8 nm inother embodiments. Further, source/drain regions 25 are formed adjacentto the gate structures, and spaces between the gate structures arefilled with a first interlayer dielectric (HD) layer 50. The first ILDlayer 50 includes one or more layers of insulating material, such asSiO₂, SiON, SiOCN, or SiCN. In one embodiment, SiO₂ is used. In thisdisclosure, a source and a drain are interchangeably used and“source/drain” refers to one of a source and a drain.

FIG. 1C is an enlarged view of the gate structure. The metal gatestructure 40 includes one or more layers 45 of metal material, such asAl, Cu, W, Ti, Ta, TiN, TiAl, TiAlC, TiAlN, TaN, NiSi, CoSi, and otherconductive materials. A gate dielectric layer 42 disposed between thechannel layer and the metal gate electrode 44 includes one or morelayers of metal oxides such as a high-k metal oxide. Examples of metaloxides used for high-k dielectrics include oxides of Li, Be, Mg, Ca, Sr,Sc, Y, Zr, Hf, Al, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb,Lu, and/or mixtures thereof. In some embodiments, an interfacedielectric layer 41 made of, for example silicon dioxide, is formedbetween the channel layer and the gate dielectric layer 42.

In some embodiments, one or more work function adjustment layers 43 areinterposed between the gate dielectric layer 42 and the metal material45. The work function adjustment layers 43 are made of a conductivematerial such as a single layer of TiN, TaN, TaAlC, TiC, TaC, Co, Al,TiAl, HtTi, TiSi, TaSi or TiAlC, or a multilayer of two or more of thesematerials. For the n-channel FET, one or more of TaN, TaAlC, TiN, TiC,Co, TiAl, TiSi and TaSi is used as the work function adjustment layer,and for the p-channel FET, one or more of TiAlC, TiAl, TaN, TaAlC, TiN,TiC and Co is used as the work function adjustment layer.

In this embodiment, fin field effect transistors (Fin FETs) fabricatedby a gate-replacement process are employed.

FIG. 1D shows an exemplary perspective view of a Fin FET structure.

First, a fin structure 310 is fabricated over a substrate 300. The finstructure includes a bottom region and an upper region as a channelregion 315. The substrate is, for example, a p-type silicon substratewith an impurity concentration in a range from about 1×10¹⁵ cm⁻³ toabout 1×10¹⁸ cm⁻³. In other embodiments, the substrate is an n-typesilicon substrate with an impurity concentration in a range from about1×10¹⁵ cm⁻³ to about 1×10¹⁸ cm⁻³. Alternatively, the substrate maycomprise another elementary semiconductor, such as germanium; a compoundsemiconductor including Group IV-IV compound semiconductors such as SiCand SiGe, Group III-V compound semiconductors such as GaAs, GaP, GaN,InP, InAs, InSb, GaAsP, AlGaN, AlInAs, AlGaAs, GaInAs, GaInP, and/orGaInAsP; or combinations thereof. In one embodiment, the substrate is asilicon layer of an SOI (silicon-on-insulator) substrate.

After forming the fin structure 310, an isolation insulating layer 320is formed over the fin structure 310. The isolation insulating layer 320includes one or more layers of insulating materials such as siliconoxide, silicon oxynitride or silicon nitride, formed by LPCVD (lowpressure chemical vapor deposition), plasma-CVD or flowable CVD. Theisolation insulating layer may be formed by one or more layers ofspin-on-glass (SOG), SiO, SiON, SiOCN and/or fluorine-doped silicateglass (FSG).

After forming the isolation insulating layer 320 over the fin structure,a planarization operation is performed so as to remove part of theisolation insulating layer 320. The planarization operation may includea chemical mechanical polishing (CMP) and/or an etch-back process. Then,the isolation insulating layer 320 is further removed (recessed) so thatthe upper region of the fin structure is exposed.

A dummy gate structure is formed over the exposed fin structure. Thedummy gate structure includes a dummy gate electrode layer made of polysilicon and a dummy gate dielectric layer. Sidewall spacers 350including one or more layers of insulating materials are also formed onsidewalls of the dummy gate electrode layer. After the dummy gatestructure is formed, the fin structure 310 not covered by the dummy gatestructure is recessed below the upper surface of the isolationinsulating layer 320. Then, a source/drain region 360 is formed over therecessed fin structure by using an epitaxial growth method. Thesource/drain region may include a strain material to apply stress to thechannel region 315.

Then, an interlayer dielectric layer (ILD) 370 is formed over the dummygate structure and the source/drain region 360. After a planarizationoperation, the dummy gate structure is removed so as to make a gatespace. Then, in the gate space, a metal gate structure 330 including ametal gate electrode and a gate dielectric layer, such as a high-kdielectric layer, is formed. In FIG. 1D, the view of parts of the metalgate structure 330, sidewalls 350 and the ILD 370 are cut to show theunderlying structure.

The metal gate structure 330 and the sidewalls 350, source/drain 360 andthe ILD 370 of FIG. 1D substantially correspond to the metal gatestructure 40, source/drain regions 25 and first interlayer dielectriclayer (ILD) 50, of FIGS. 1A and 1B, respectively.

FIGS. 2-13 show exemplary cross sectional views corresponding to lineX1-X1 of FIG. 1A, illustrating various stages of the sequentialfabrication process of a semiconductor device according to oneembodiment of the present disclosure. It is understood that additionaloperations can be provided before, during, and after processes shown byFIGS. 2-13, and some of the operations described below can be replacedor eliminated, for additional embodiments of the method. The order ofthe operations/processes may be interchangeable.

As shown in FIG. 2, the metal gate electrodes 44 are recessed below theupper surface of the sidewall spacers 46 by a dry and/or a wet etchingoperation. The remaining height H1 of the recessed gate electrode 44 isin a range from about 15 nm to about 50 nm in some embodiments.

After the gate electrodes 44 are recessed, a blanket layer 61 of a firstinsulating material is formed, as shown in FIG. 2. The first insulatingmaterial includes one or more of SiC, SiON, SiOCN, SiCN and SiN.

A planarization operation, such as an etch-back process or a chemicalmechanical polishing (CMP) process, is performed on the blanket layer61, so that the gate cap insulating layers 60 are formed over the gateelectrode 44, as shown in FIG. 3.

As shown in FIG. 4, the first ILD layer 50 is removed by a thy and/or awet etching, thereby forming openings 65 and exposing the source/drainstructures 25 at the bottoms of the openings 65.

Subsequently, a blanket layer of a first conductive material 71 isformed, as shown in FIG. 5. The first conductive material 71 includesone or more of W, Co, Ni, or Ti. At the interface between the firstconductive material 71 and the source/drain structure 25, a silicidelayer, such as WSi, CoSi₂ or TiSi, may be formed. In one embodiment, Wis used.

A planarization operation, such as an etch-back process or a CMPprocess, is performed on the blanket layer 71, so that the source/drainconductive layers 70 are formed over the source/drain regions 25, asshown in FIG. 6.

Then, as shown in FIG. 7, the source/drain conductive layers 70 arerecessed below the upper surface of the sidewall spacers 46 by a dryand/or a wet etching operation. The remaining height H2 of the recessedsource/drain conductive layer 70 is in a range from about 15 nm to about50 nm in some embodiments.

Subsequently, a blanket layer of a second insulating material 81 isformed, as shown in FIG. 8. The second insulating material 81 isdifferent from the first insulating material 61 and includes one or moreof SiC, SiON, Al₂O₃, SiOCN, SiCN and SiN. The two materials for thefirst and second insulating materials are interchangeable to fulfilldifferent process requirements.

A planarization operation, such as an etch-back process or a CMPprocess, is performed on the blanket layer 81, so that the source/draincap insulating layers 80 are formed over the source/drain conductivelayers 70, as shown in FIG. 9. As shown in FIG. 9, plural gatestructures extending in the Y direction are arranged in the X directionwith an equal interval. Each of the gate structures includes a gateelectrode 44, a gate cap insulating layer 60 disposed over the gateelectrode 44, sidewall spacers 46 disposed on opposing side faces of thegate electrode 44 and the gate cap insulating layer 60. Further, pluralsource; drain structures are disposed between adjacent two gatestructures. Each of the source/drain structure includes a source/drainconductive layer 70 and a source/drain cap insulating layer 80 disposedon the source/drain conductive layer 70.

The thickness H4 of the gate cap insulating layer 60 is in a range fromabout 10 nm to about 40 nm in some embodiments. The thickness H3 of thesource/drain cap insulating layer 80 is in a range from about 10 nm toabout 40 nm in some embodiments.

Next, as shown in FIG. 10, at least one gate structure (e.g., gatestructures 40C and 40D) and at least one source/drain structure with thesource/drain cap insulating layer are covered by a first mask layer 72,while at least one gate structure (e.g., 40A and 40B) and at least onesource/drain structure with the source/drain cap insulating layer areexposed. Then, the gate cap insulating layers 60 are selectivelyremoved, thereby forming a gate opening 85.

Here, the gate cap insulating layer 60, the source/drain cap insulatinglayer 80 and the sidewall spacers 45 are made of different insulatingmaterials. In particular, the source/drain cap insulating layer 80 andthe sidewall spacers 45 are materials having a high etching selectivity(about 4 or more) with respect to the gate cap insulating layer 60 inthe etching of the gate cap insulating layer 60. In some embodiments,the etching selectivity is about 6 to 20. Accordingly, the gate capinsulating layers 60 can be selectively removed in a self-alignedmanner. As shown in FIG. 10, an edge of the opening pattern of the firstmask layer 72 may be located on at least one source/drain cap insulatinglayer 80.

In some embodiments, a second ILD layer 110 (see, FIG. 24) made of, forexample, SiO₂ (or one or more of SiON, SiOCN, SiCN or SiCO), is formedover the structure of FIG. 9 before forming the first mask layer 72. Insuch a case, the second ILD is first etched by using the first masklayer 72 as an etching mask, and then the gate cap insulating layers 60are etched. The etching condition for etching the second ILD may bedifferent from the etching condition for etching the gate cap insulatinglayers.

Similarly, as shown in FIG. 11, at least one gate structure (e.g., gatestructures 40A and 40A) and at least one source/drain structure with thesource/drain cap insulating layer are covered by a second mask layer 74,while at least one gate structure (e.g., 40D) and at least onesource/drain structure with the source/drain cap insulating layer areexposed. Then, the source/drain cap insulating layer 80 are selectivelyremoved, thereby forming a source/drain opening 87. Here, the gate capinsulating layer 60 and the sidewall spacers 45 are materials having ahigh etching selectivity (about 4 or more) with respect to thesource/drain cap insulating layer 80 in the etching of the source/draincap insulating layer 80. In some embodiments, the etching selectivity isabout 6 to 20. Accordingly, the source/drain cap insulating layers 80can be selectively removed in a self-aligned manner. As shown in FIG.11, an edge of the opening pattern of the second mask layer 74 may belocated on at least one gate cap insulating layer 60.

The order of the removal of the gate cap insulating layer 60 and theremoval of the source/drain cap insulating layer 80 is interchangeable.

Subsequently, a blanket layer 101 of a second conductive material isformed, as shown in FIG. 12. The second conductive material includes oneor more of Cu, W, Co, Ni, Ti or an alloy thereof.

A planarization operation, such as an etch-back process or a CMPprocess, is performed on the blanket layer 101, so that gate contactlayers 100 and source/drain contact layers 105 are formed over the gateelectrode 44 and the source/drain conductive layers 70, as shown in FIG.13.

It is understood that the device shown in FIG. 13 undergoes further CMOSprocesses to form various features such as interconnect metal layers,dielectric layers, passivation layers, etc.

FIGS. 14-23 show exemplary cross sectional views illustrating variousstages of the sequential fabrication process of a semiconductor deviceaccording to another embodiment of the present disclosure. It isunderstood that additional operations can be provided before, during,and after processes shown by FIGS. 14-23, and some of the operationsdescribed below can be replaced or eliminated, for additionalembodiments of the method. The order of the operations/processes may beinterchangeable. The configurations, structures, materials, processesand/or operations substantially the same as those for the foregoingembodiment may be applied to this embodiment, and the detailedexplanation thereof may be omitted.

After the structure of FIG. 3 is formed, at least one of thesource/drain regions with the first ILD 50 is covered by a mask layer53, as shown in FIG. 14. The mask layer 53 includes a hard mask layer 52and an organic resin layer 54. The hard mask layer 52 includes one ormore layers of TiN, SiN, Ti, Si, TiO₂ and SiO₂. In one embodiment, thestacked layer of SiO₂/Si/SiO₂ is used. On the silicon/oxide stack layerof the hard mask layer 52, a photo resist layer or a bottom antireflection coating layer 54 is formed.

By using the mask layer 53 as an etching mask, the first ILD layers 50are removed from the source/drain regions not covered by the mask layer53.

Then, similar to FIG. 5, a blanket layer of a first conductive material71 is formed, as shown in FIG. 15. Before forming the first conductivematerial layer, at least the organic resin layer 54 is removed.Subsequently, a planarization operation, such as an etch-back process ora CMP process, is performed on the blanket layer 71, so that thesource/drain conductive layers 70 are formed over the source/drainregions 25, as shown in FIG. 16. By the planarization operation, thehard mask layer 52 is removed.

Next, similar to FIG. 7, the source/drain conductive layers 70 arerecessed below the upper surface of the sidewall spacers 46 by a dryand/or a wet etching operation, as shown in FIG. 17.

Subsequently, similar to FIG. 8, a blanket layer of a second insulatingmaterial 81 is formed, as shown in FIG. 18. Similar to FIG. 9, aplanarization operation, such as an etch-back process or a CMP process,is performed on the blanket layer 81, so that the source/drain capinsulating layers 80 are formed over the source/drain conductive layers70, as shown in FIG. 19.

Next, similar to FIG. 10, at least one gate structure (e.g., gatestructures 40C and 40D) and at least one source/drain structure with thesource/drain cap insulating layer are covered by a first mask layer 72,while at least one gate structure (e.g., 40A and 40B) and at least onesource/drain structure with the source/drain cap insulating layer areexposed. Then, the gate cap insulating layers 60 are selectivelyremoved, thereby forming a gate opening 85, as shown in FIG. 20. Asshown in FIG. 20, an edge of the opening pattern of the first mask layer72 may be located on the first ILD layer 50 disposed on at least onesource/drain region 25.

Here, the gate cap insulating layer 60, the source/drain cap insulatinglayer 80, the sidewall spacers 45, and the first ILD layer 50 are madeof different insulating materials. In particular, the source/drain capinsulating layer 80, the sidewall spacers 45 and the first HD layer 50are materials having a high etching selectivity (about 4 or more) withrespect to the gate cap insulating layer 60 in the etching of the gatecap insulating layer 60. In some embodiments, the etching selectivity isabout 6 to 20, Accordingly, the gate cap insulating layers 60 can beselectively removed in a self-aligned manner.

Similar to FIG. 11, at least one gate structure (e.g., gate structures40A and 40B) and at least one source/drain structure with thesource/drain cap insulating layer are covered by a second mask layer 74,while at least one gate structure (e.g., 40D) and at least onesource/drain structure with the source/drain cap insulating layer areexposed. Then, the source/drain cap insulating layer 80 are selectivelyremoved, thereby forming a source/drain opening 87, as shown in FIG. 21.As shown in FIG. 21, an edge of the opening pattern of the second masklayer 74 may be located on at least one gate cap insulating layer 60.

The order of the removal of the gate cap insulating layer 60 and theremoval of the source/drain cap insulating layer 80 is interchangeable.

Subsequently, similar to FIG. 12, a blanket layer 101 of a secondconductive material is formed, as shown in FIG. 22. A planarizationoperation, such as an etch-back process or a CMP process, is performedon the blanket layer 101, so that gate contact layers 100 andsource/drain contact layers 105 are formed over the gate electrode 44and the source/drain conductive layers 70, as shown in FIG. 23.

It is understood that the device shown in FIG. 23 undergoes further CMOSprocesses to form various features such as interconnect metal layers,dielectric layers, passivation layers, etc.

The various embodiments or examples described herein offer severaladvantages over the existing art.

FIG. 24 shows an exemplary cross sectional view illustrating one ofadvantages of the present embodiments.

FIG. 24 illustrate the structure, when a mask pattern having an opening(e.g., a contact hole pattern) above the gate electrode 44 ismis-aligned, for example, to the left by the amount of D1 due to processvariation. With the mask pattern, the second ILD layer 110 is etched,and then the gate cap insulating layer 60 is etched. Because of themis-alignment, a part of the sidewall spacers 46 and/or a part of thesource/drain cap insulating layer 80 may be etched. However, the etchingelectivity of the sidewall spacers 46 and the source/drain capinsulating layer 80 are sufficiently high against the gate capinsulating layer 60, the amount of such an etching can be minimized.Accordingly, the gate contact 100 can be formed in a self-aligned manneravoiding a short-circuit to the source/drain conductive layer 70.

Similarly, as shown in FIG. 24, a mask pattern having an opening (e.g.,a contact hole pattern) above the source/drain conductive layer 70 maybe mis-aligned, for example, to the right by the amount of D2 due toprocess variation. With the mask pattern, the second ILD layer 110 isetched, and then the source/drain cap insulating layer 80 is etched.Because of the mis-alignment, a part of the sidewall spacers 46 and/or apart of the gate cap insulating layer 60 may be etched. However, theetching electivity of the sidewall spacers 46 and the gate capinsulating layer 80 are sufficiently high against the source/drain capinsulating layer 80, the amount of such an etching can be minimized.Accordingly, the source/drain contact 105 can be formed in aself-aligned manner avoiding a short-circuit to the gate electrode 44.

Because of the above advantages of the self-align contacts, it is alsopossible to reduce a gate pattern density.

FIG. 25 shows an exemplary layout structure according to one embodimentof the present disclosure. FIG. 25 shows an exemplary layout structurearound a cell boundary of two standard cells.

In FIG. 25, four gate patterns P40 extending in the Y direction arearranged in the X direction with an equal interval. Source/drainpatterns P70 are disposed between the adjacent two gate patterns. Gatecontact patterns P100A are disposed over the gate patterns above a finpattern P20. A gate contact pattern P100B is also disposed over the gatepatterns above an area other than the fin pattern P20. Source/draincontacts P105 are disposed over the source/drain patterns P70.

In the present embodiments, since the gate contact 100 can be formed ina self-aligned manner substantially free from a short-circuit to thesource/drain conductive layer 70, the gate contact pattern P100A (gatecontact 100) can be arranged over the fin pattern P20 (fin structure 20)in which the source/drain patterns P70 (source/drain conductive layer70) are disposed, as shown in area A1 of FIG. 25.

Similarly, in area A2 of FIG. 25, the gate contact pattern P100B can bearranged closer to the fin pattern P20. The space Si between the gatecontact pattern P100B and the fin pattern P20 is less than about 15 nmand in a range from about 5 nm to about 12 nm in some embodiments.

Accordingly, it is possible to reduce a gate pattern density.

It will be understood that not all advantages have been necessarilydiscussed herein, no particular advantage is required for allembodiments or examples, and other embodiments or examples may offerdifferent advantages.

According to one aspect of the present disclosure, in a method ofmanufacturing a semiconductor device, gate structures extending in afirst direction and arranged in a second direction crossing the firstdirection are formed. Each of the gate structures includes a gateelectrode, a gate cap insulating layer disposed over the gate electrode,sidewall spacers disposed on opposing side faces of the gate electrodeand the gate cap insulating layer. Source/drain structures are formedbetween adjacent two gate structures. Each of the source/drainstructures includes a source/drain conductive layer and a source/draincap insulating layer disposed on the source/drain conductive layer. Thegate cap insulating layer is selectively removed from at least one ofthe gate structures, while at least one of remaining gate structures isprotected, thereby exposing the gate electrode of the at least one ofthe gate structures. The source/drain cap insulating layer isselectively removed from at least one of the source/drain structures,while at least one of remaining source/drain structures is protected,thereby exposing the source/drain conductive layer of the at least oneof the source/drain structures. Conductive contact layers are formed onthe exposed gate electrode and the exposed source/drain conductivelayer.

According to another aspect of the present disclosure, in a method ofmanufacturing a semiconductor device, a first gate structure, a secondgate structure, a third gate structure and a fourth gate structure,which extend in a first direction, are formed over a substrate. Thefirst gate structure includes a first gate electrode, a first gatedielectric layer, first sidewall spacers disposed on opposing side facesof the first gate electrode. The second gate structure includes a secondgate electrode, a second gate dielectric layer, second sidewall spacersdisposed on opposing side faces of the second gate electrode. The thirdgate structure includes a third gate electrode, a third gate dielectriclayer, third sidewall spacers disposed on opposing side faces of thethird gate electrode. The fourth gate structure includes a fourth gateelectrode, a fourth gate dielectric layer, fourth sidewall spacersdisposed on opposing side faces of the fourth gate electrode. The firstto the fourth gate structures are arranged in a second directioncrossing the first direction. A first source/drain region is formedbetween the first and second gate structures, a second source/drainregion is formed between the second and third gate structures, and athird source/drain region is formed between the third and fourth gatestructures. A first insulating layer is formed over the first to thirdsource/drain regions. The first to fourth gate electrodes are recessedbelow upper surfaces of the first to fourth sidewall spacers, therebyforming a first to a fourth gate opening, respectively. A first to afourth gate cap insulating layer are formed in the first to the fourthgate openings, respectively. The first insulating layer is removed so asto expose the first and third source/drain regions. A first and a thirdsource/drain conductive layers are formed over the first and thirdsource/drain regions, respectively. The first and the third source/drainconductive layers are recessed below upper surfaces of the first tofourth sidewall spacers, thereby forming a first and a thirdsource/drain opening, respectively. A first and a third source/drain capinsulating layer are formed in the first and the third source/drainopenings, respectively. The first and second gate cap insulating layersare removed, while protecting the third and fourth gate cap insulatinglayers and the third source/drain cap insulating layer, thereby exposingthe first and second gate electrodes. The third source; drain capinsulating layer is removed, while protecting the first source/drain capinsulating layer, thereby exposing the third source/drain region.Conductive contact layers are formed on the exposed first and secondgate electrodes and the exposed third source/drain region.

In accordance with yet another aspect of the present disclosure, asemiconductor device includes a first gate structure, a second gatestructure, a first source/drain structure and a second source/drainstructure. The first gate structure includes a first gate electrode anda first cap insulating layer disposed on the first gate electrode. Thesecond gate structure includes a second gate electrode and a firstconductive contact layer disposed on the first gate electrode. The firstsource/dram structure includes a first source/drain conductive layer anda second cap insulating layer disposed over the first source/drainconductive layer. The second source/drain structure includes a secondsource/drain conductive layer and a second conductive contact layerdisposed over the second source/drain conductive layer.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method of manufacturing a semiconductor device,the method comprising: forming gate structures extending in a firstdirection and arranged in a second direction crossing the firstdirection, each of the gate structures including a gate electrode, agate cap insulating layer disposed over the gate electrode, sidewallspacers disposed on opposing side faces of the gate electrode and thegate cap insulating layer; forming source/drain structures onsource/drain epitaxial layers between adjacent two gate structures, eachof the source/drain structures including a source/drain conductive layerand a source/drain cap insulating layer disposed on the source/drainconductive layer; forming a first mask layer having a first opening overthe gate structures and the source/drain structures, wherein under thefirst opening, tops of the sidewall spacers disposed on opposing sidefaces of the gate electrode and the gate cap insulating layer of the atleast one of the gate structures are exposed, and at least one edge ofthe first opening is located on the source/drain cap insulating layer ofone of the source/drain structures; selectively removing the gate capinsulating layer through the first opening from at least one of the gatestructures, while protecting at least one of remaining gate structures,thereby exposing the gate electrode of the at least one of the gatestructures, wherein the gate cap insulating layer is fully removed fromthe at least one of the gate structures under the first opening; forminga second mask layer having a second opening over the gate structures andthe source/drain structures, wherein under the second opening, a top ofone of the sidewall spacers of one of the gate structures and a top ofone of the sidewall spacers of adjacent one of the gate structures areexposed, and at least one edge of the second opening is located on thegate cap insulating layer of one of the gate structures; selectivelyremoving the source/drain cap insulating layer through the secondopening from at least one of the source/drain structures, whileprotecting at least one of remaining source/drain structures, therebyexposing the source/drain conductive layer of the at least one of thesource/drain structures, wherein the source/drain cap insulating layeris fully removed from the at least one of the source/drain structuresunder the second opening; and forming conductive contact layers on theexposed gate electrode and the exposed source/drain conductive layer,wherein the forming conductive contact layers includes: forming aconductive material over the exposed gate electrode, the exposedsource/drain conductive layer, the at least one of remaining gatestructures and the at least one of remaining source/drain structures,and performing a chemical mechanical polishing operation such that thegate cap insulating layer of the at least one of remaining gatestructures and the source/drain cap insulating layer of the at least oneof remaining source/drain structures are exposed.
 2. The method of claim1, wherein in the selectively removing the gate cap insulating layer ofthe at least one of the gate structures, at least one source/drain capinsulating layer is not protected.
 3. The method of claim 1, wherein inthe selectively removing the source/drain cap insulating layer of the atleast one of the source/drain structures, at least one gate capinsulating layer is not protected.
 4. The method of claim 1, wherein anupper surface of the gate electrode of each of the gate structures islocated at a different level from an upper surface of the source/drainconductive layer of each of the source/drain structures.
 5. The methodof claim 4, wherein the upper surface of the gate electrode of each ofthe gate structures is located at a lower level than the upper surfaceof the source/drain conductive layer of each of the source/drainstructures.
 6. The method of claim 1, wherein the gate cap insulatinglayer of each of the gate structures is made of different material thanthe source/drain cap insulating layer of each of the source/drainstructures.
 7. The method of claim 6, wherein the gate cap insulatinglayer of each of the gate structures and the source/drain cap insulatinglayer of each of the source/drain structures are made of at least one ofSiC, SiOCN, SiON, SiCN and SiN.
 8. The method of claim 1, wherein thesidewall spacers of each of the gate structures are made of differentmaterial than the gate cap insulating layer of each of the gatestructures and the source/drain cap insulating layer of each of thesource/drain structures.
 9. The method of claim 8, wherein the sidewallspacers of each of the gate structures are made of at least one of SiC,SiON, Al₂O₃, SiOCN, SiCN and SiN.
 10. The method of claim 1, wherein athickness of the gate cap insulating layer is greater than a thicknessof the source/drain cap insulating layer.
 11. A method of manufacturinga semiconductor device, the method comprising: forming a first gatestructure, a second gate structure, a third gate structure and a fourthgate structure, which extend in a first direction, over a substrate, thefirst gate structure including a first gate electrode, a first gatedielectric layer, first sidewall spacers disposed on opposing side facesof the first gate electrode, the second gate structure including asecond gate electrode, a second gate dielectric layer, second sidewallspacers disposed on opposing side faces of the second gate electrode,the third gate structure including a third gate electrode, a third gatedielectric layer, third sidewall spacers disposed on opposing side facesof the third gate electrode, the fourth gate structure including afourth gate electrode, a fourth gate dielectric layer, fourth sidewallspacers disposed on opposing side faces of the fourth gate electrode,the first to the fourth gate structures being arranged in a seconddirection crossing the first direction; forming a first source/drainregion between the first and second gate structures, a secondsource/drain region between the second and third gate structures, and athird source/drain region between the third and fourth gate structures;forming a first insulating layer over the first to third source/drainregions; recessing the first to fourth gate electrodes below uppersurfaces of the first to fourth sidewall spacers, thereby forming afirst to a fourth gate opening, respectively; forming a first to afourth gate cap insulating layer in the first to the fourth gateopenings, respectively; removing the first insulating layer so as toexpose the first, second and third source/drain regions; forming afirst, a second and a third source/drain conductive layers over thefirst, second and third source/drain regions, respectively; recessingthe first, the second and the third source/drain conductive layers belowupper surfaces of the first to fourth sidewall spacers, thereby forminga first, a second and a third source/drain opening, respectively;forming a first, a second and a third source/drain cap insulating layerin the first, the second and the third source/drain openings,respectively; removing the first and second gate cap insulating layers,while protecting the third and fourth gate cap insulating layers and thethird source/drain cap insulating layer, thereby exposing the first andsecond gate electrodes, and exposing the first and second source/draincap insulating layers; removing the third source/drain cap insulatinglayer, while protecting the first source/drain cap insulating layer,thereby exposing the third source/drain conductive layer, and exposingthe third and fourth gate cap insulating layers; and forming conductivecontact layers on the exposed first and second gate electrodes and theexposed third source/drain conductive layer, wherein the formingconductive contact layers includes: forming a conductive material overthe exposed first and second gate electrodes and the exposed thirdsource/drain conductive layer, the third and fourth gate cap insulatinglayers and the first source/drain cap insulating layer, and performing achemical mechanical polishing operation such that the third and fourthgate cap insulating layers and the first source/drain cap insulatinglayer are exposed.
 12. The method of claim 11, wherein: the first tofourth gate cap insulating layers are made of different material thanthe first and third source/drain cap insulating layers, the first tofourth gate cap insulating layers and the first and third source/draincap insulating layers are made of at least one of SiC, SiON, SiOCN, SiCNand SiN, the first to fourth sidewall spacers are made of differentmaterial than the first to the fourth gate cap insulating layers and thefirst and third source/drain cap insulating layer, and the first tofourth sidewall spacers are made of at least one of SiC, SiON, Al₂O₃,SiOCN, SiCN and SiN.
 13. The method of claim 11, wherein a thickness ofthe first to fourth gate cap insulating layers is greater than athickness of the first to third source/drain cap insulating layers. 14.The method of claim 11, wherein: the first and second gate capinsulating layers are fully removed through a first opening formed in afirst mask layer, and the third source/drain cap insulating layers arefully removed through a second opening formed in a second mask layer.15. A method of manufacturing a semiconductor device, the methodcomprising: forming a gate structure over a substrate, the gatestructure including a gate electrode, a gate dielectric layer and firstsidewall spacers; forming a source/drain region; forming a firstinsulating layer over the source/drain region; recessing the gateelectrode of the gate structure below upper surfaces of the firstsidewall spacers, thereby forming a gate opening over the recessed gateelectrode; forming a gate cap insulating layer in the gate opening;removing the first insulating layer so as to expose the source/drainregion; forming a source/drain conductive layer over the source/drainregion; recessing the source/drain conductive layer below the uppersurfaces of the first sidewall spacers, thereby forming a source/drainopening over the recessed source/drain conductive layer; forming asource/drain cap insulating layer in the source/drain opening; forming afirst mask layer having a first opening over the gate cap insulatinglayer, wherein under the first opening, tops of the first sidewallspacers and the gate cap insulating layer of the gate structure areexposed, and at least one edge of the first opening is located onanother source/drain cap insulating layer different from thesource/drain cap insulating layer; removing the gate cap insulatinglayer through the first opening, thereby exposing the recessed gateelectrode wherein the gate cap insulating layer is fully removed underthe first opening; forming a second mask layer having a second openingover the source/drain cap insulating layer, wherein under the secondopening, a top of one of second sidewall spacers different from thefirst sidewall spacers and a top of one of third sidewall spacersdifferent from the first sidewall spacers are exposed, and at least oneedge of the second opening is located on another gate cap insulatinglayer different from the gate cap insulating layer; removing thesource/drain cap insulating layer through the second opening, therebyexposing the recessed source/drain conductive layer wherein thesource/drain cap insulating layer is fully removed under the secondopening; and forming conductive contact layers on the exposed recessedgate electrodes and the exposed recessed source/drain conductive layerby a same operation, wherein: the removing the gate cap insulating layerand the removing the source/drain cap insulating layer are performed bydifferent etching operations, and the forming conductive contact layersincludes: forming a conductive material over exposed recessed gateelectrodes and the exposed recessed source/drain conductive layer, andthe first sidewall spacers, and performing a chemical mechanicalpolishing operation such that the first sidewall spacers are exposed.16. The method of claim 15, wherein the removing the gate cap insulatinglayer is performed before the removing the source/drain cap insulatinglayer.
 17. The method of claim 16, wherein the gate cap insulating layeris removed while protecting the source/drain cap insulating layer. 18.The method of claim 15, wherein a thickness of the gate cap insulatinglayer is greater than a thickness of the source/drain cap insulatinglayer.